Method for Preparing a Non-Ionic Surfactant Stable Personal Care Dispersion

Abstract

Disclosed herein are methods for preparing dispersions containing small diameter, liquid crystals of a high charge density cationic polymer and a detersive surfactant. Also disclosed herein are uses of these dispersions to prepare personal care products and liquid cleansing products.

Description

CROSS REFERENCE TO RELATED APPLICATION[0001]This application claims the benefit of U.S. Provisional Application No. 61 / 352,977 filed Jun. 9, 2010.FIELD OF THE INVENTION[0002]The present invention relates to methods for preparing a dispersion containing small diameter, liquid crystals of a high charge density cationic polymer and a detersive surfactant, and use of these dispersions to prepare personal care products and liquid cleansing products.BACKGROUND OF THE INVENTION[0003]Conditioning personal care compositions containing lyotropic liquid crystals are known to reduce the surface energy of hair, thereby increasing its hydrophobicity and restoring its natural, smooth, lubricious feel. Lyotropic liquid crystals are often composed of a detersive surfactant and a high charge density cationic polymer in water. In effect, when a detersive surfactant and high charge density cationic polymer are added together in water, an ionic interaction results between them, which induces areas of li...

AI Technical Summary

Benefits of technology

[0007]Disclosed herein are methods for forming a dispersion containing liquid crystals of a high charge density cationic polymer and a detersive surfactant at ambient temperature (about 20° C. to about 40° C.). In this method, a synthetic, cationic polymer that has a cationic charge density of at least about 2 molar equivalents per gram (meq / g), in one embodiment at least about 5 meq / g, for example, about 7 meq / g, is added to a neutralized, preserved, detersive surfactant at a rate sufficient to provide an instantaneous weight ratio of cationic polymer to forming dispersion of about 1:10 to about 1:100, in one embodiment from about 1:12.5 to about 1:50, in another embodiment from about 1:15 to about 1:30. Further, during addition of the cationic polymer the forming dispersion has an energy of about 10 Joules per kilogram (J / kg) to about 10,000 J / kg, in one embodiment from about 100 J / kg to about 7,500 J / kg, in another embodiment from about 500 J / kg to about 5000 J / kg. The resulting dispersion can have a final cationic polymer concentration of about 1 wt. % to about 10 wt. %, in one embodiment from about 3 wt. % to about 6 wt. %, for example, about 4 wt. % of the cationic polymer, based on the total weight of the dispersion. Optionally, the resulting dispersion is stabilized from settling and creaming through the addition of a suspending agent. The liquid crystals that form in the dispersion have an average diameter of less than about 100 μm, in one embodiment from about 1 μm to about 20 μm.

Problems solved by technology

A rapid charge-charge interaction between the high charge density cationic polymer and detersive surfactant results in liquid crystals with undesirable, large diameters, while a slow charge-charge interaction results in liquid crystals with desirable, small diameters.

Because so many parameters influence the rate charge-charge interaction, controlling it has traditionally proved especially difficult.

Thus, every time a new conditioning personal care product is formulated, the parameters controlling liquid crystal formation must be reoptimized, resulting in significant time and cost disadvantages.

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